Endoscopic inspection using a flexible sleeve

ABSTRACT

An endoscopic apparatus including an internal unit, adapted to be advanced into a gastrointestinal tract of a patient so as to enable inspection of the tract, an anchor unit, adapted to be held in a position outside the gastrointestinal tract and a flexible sleeve, having a proximal end fixed to the anchor and a distal end fixed to the internal unit, wherein at least a portion of the sleeve between the proximal end distal ends is held initially in a compact state at the internal unit and is arranged to feed out from the internal unit as the internal unit is advanced into the gastrointestinal tract. A method for endoscopic examination is also disclosed.

This application is a continuation of U.S. patent application Ser. No.09/646,941, filed Nov. 13, 2000, now U.S. Pat. No. 6,485,409.

FIELD OF THE INVENTION

The present invention relates generally to propulsion of objects withinlumens, and specifically to methods and devices for propelling medicalinstruments through the colon

BACKGROUND OF THE INVENTION

The use of an endoscope for examining a body cavity is well known in theart The diagnostic and therapeutic advantages conferred by directexamination of the gastrointestinal tract with a flexible endoscope havemade this method a standard procedure of modern medicine. One of themost common endoscopic procedures is colonoscopy, which is performed fora wide variety of purposes, including diagnosis of cancer, determinationof the source of gastrointestinal bleeding, viewing a site affected byinflammatory bowel disease, removing polyps, and reducing volvulus andintussusception.

While colonoscopy is useful and effective, it is a difficult procedurefor a physician to perform and is painful and occasionally dangerous forthe patient These problems stem from the need to push and steer thelong, flexible colonoscope through the intestine by pushing it in fromits proximal end, outside the body.

It would be desirable to provide a propulsion mechanism to push or pullthe endoscope forward from its distal end, inside the body. A number ofmethods and devices have been proposed for this purpose, although nonehas achieved clinical or commercial acceptance.

U.S. Pat. No. 4,207,872 to Meiri et al., whose disclosure isincorporated herein by reference, describes a device and method foradvancing an endoscope through a body passage utilizing multiplefluid-filled flexible protrusions distributed along an outer surface ofa sleeve containing the endoscope. Alternately increasing and decreasingthe fluid pressure within the protrusions advances the endoscope along abody passage. Each protrusion is in direct contact with an inner surfaceof the body passage and applies local contact pressure against thisrelatively small contact surface in order to propel the endoscopeforward.

U.S. Pat. No. 3,895,637 to Choy, whose disclosure is incorporated hereinby reference, describes a device able to move through a tubular organ bysequentially inflating and deflating first and second radiallyinflatable members The inflation anchors the inflated member against alocal region of the tubular organ, while air pressure in alongitudinally inflatable communicating part of the device moves thenon-anchored part of the device longitudinally through the tubular organSufficient contact pressure of the inflated member against a relativelysmall length of the tubular organ is required in order for the device tobe able to progress through the organ U.S. Pat. No. 3,895,637 has noprovision to distribute the contact pressure over a larger area of thetissue against which it presses in order to generate longitudinalmotion.

U.S. Pat. No. 4,321,915 to Leighton et al, whose disclosure isincorporated herein by reference, describes an everting tube device forintroducing a tool into a body cavity using alternating steps ofapplying positive pressure to evert the tube and advance the tool, andapplying a vacuum to pull the everted tube away from the tool so that anoperator can retract the tool one half of the distance it advanced inthe previous step The operator using this device is required to manuallywithdraw the tool the prescribed distance during every pressure cycle inorder to avoid causing the tool to advance too far beyond the tip of theeverted tube

U.S. Pat. No. 4,403,985 to Boretos, whose disclosure is incorporatedherein by reference, describes a jet-propelled device for insertion intobody passageways Pressurized fluid is passed to the device from outsideof the body and then ejected from an orifice in the device in onedirection in order to propel the device in the opposite direction. Thedevice of U.S. Pat. No. 4,403,985 thus generates propulsion by expellingmaterial into the body passageway

SUMMARY OF THE INVENTION

It is an object of some aspects of the present invention to provide animproved system and method for propelling an object within a lumen.

It is a further object of some aspects of the present invention toprovide an improved propulsion mechanism for advancing an endoscopewithin a body cavity of a patient for purposes of examination,diagnosis, and treatment.

In preferred embodiments of the present invention, a probe containing anendoscopic instrument is advanced through the lower gastrointestinaltract of a patient by inflation of a flexible sleeve coupled to theprobe. One end of the sleeve is anchored, typically at or adjacent tothe patient's anus. As the sleeve is inflated, preferably using apressurized gas, the probe is propelled forward, and the sleeve is fedout gradually between the probe and the anus. The portion of the sleevethat is inflated expands radially outward and remains substantiallystationary relative to the intestinal wall as long as it is inflatedLongitudinal motion of the sleeve relative to the wall generally occursonly at and adjacent to the probe itself The probe is thus advancedeasily, and trauma to the gastrointestinal tract is minimized. To removethe probe, the sleeve is deflated and is used to pull the probe back outthrough the anus.

In some preferred embodiments of the present invention, the sleeve ispassed around the probe and everts as the probe advances. Preferably,the sleeve is folded over one or more resilient rings encircling theprobe, wherein the rings most preferably comprise ring-shaped springs,which encircle the outer surface of the probe and are held against theprobe by magnetic attraction. Inflating the sleeve advances the probethrough the colon, causing the sleeve to unfold from the inside out.Thus, an external portion of the sleeve opens out only near the probe,while the rest of the external portion stays stationary.

In other preferred embodiments of the present invention, the sleeve isstored in a compact state, typically folded or rolled up, inside orimmediately adjacent to the probe. Most preferably, the folded orrolled-up probe is stored in a recess in a proximal portion of theprobe. As the probe advances, the sleeve feeds gradually out of itsstored state and expands against the intestinal wall.

In some preferred embodiments of the present invention, the probecomprises a separate steering unit for easing over or around curves inthe gastrointestinal tract and obstructions, such as blood clots, smalldeformations and other obstacles, so that the probe can move within thepatient's body while minimizing harmful contact and friction Thesteering unit preferably works by gas or fluid pressure, most preferablyas described in Israel Patent Application 125,397, which is assigned tothe assignee of the present patent application and whose disclosure isincorporated herein by reference. Alternatively, other steering methodsknown in the art may be used.

In some preferred embodiments of the present invention, the probecomprises instruments for examination, diagnosis and treatmentPreferably, the instruments include an imaging device, most preferably aminiature video camera and light source, as are known in the art, whichare used to capture endoscopic images. Means for operating theinstruments and receiving data therefrom comprise wires, fiber-opticlines, or tubes which are coupled to the instruments and extend to anoperator or to equipment outside of the patient, which operates theinstruments and receives data therefrom. The wires, line or tubespreferably pass through the sleeve.

In preferred embodiments of the present invention, advancing the probethrough the gastrointestinal tract by way of inflating the sleevereduces or eliminates the necessity of applying mechanical force at aproximal end of the probe (outside the patient's body) to insert theprobe, as is required using conventional endoscopes The presentinvention thus reduces or eliminates the necessity of applyingconcentrated, local pressure to any part the patient's body, reduces oreliminates rubbing and friction between the unit or parts of it and thepatient's body, and avoids ejecting fluids or other materials into thebody's passageway.

There is therefore provided, in accordance with a preferred embodimentof the present invention, endoscopic apparatus which advances within alumen, including:

a probe having distal and proximal ends; and

a flexible sleeve coupled proximally to the probe, which sleeve isinflated in order to propel the probe within the lumen

Preferably, the probe includes an imaging device, which captures imagesinside the lumen.

In a preferred embodiment, the sleeve everts as the probe advances,wherein the sleeve is passes around an outer surface of the probe andeverts over a retaining ring, which holds the sleeve against the outersurface of the probe Preferably, the probe includes magnetic material,and wherein the retaining ring includes one or more metal springs, whichare held against the probe by magnetic attraction thereto

Further preferably, an outer portion of the sleeve, which has evertedover the ring, is anchored so as to remain substantially stationaryrelative to a wall of the lumen.

In another preferred embodiment, a portion of the sleeve is held at theprobe in a compact state and feeds out from the proximal end of theprobe as the probe advances. Preferably, the probe has a recess adjacentto the proximal end thereof, which contains the sleeve in the compactstate Further preferably, the sleeve is anchored at a position proximalto the probe so that a portion of the sleeve that has been inflated,between the proximal position and the probe, remains substantiallystationary relative to a wall of the lumen

Preferably, the lumen includes a passage inside the body of a patient,most preferably a portion of the gastrointestinal tract

There is also provided, in accordance with a preferred embodiment of thepresent invention, a method for propelling a probe within a lumen,including

coupling a flexible sleeve to a proximal end of the probe; and inflatingthe sleeve to advance the probe through the lumen

In a preferred embodiment, the sleeve everts as the probe is advanced,wherein coupling the sleeve includes passing the sleeve around an outersurface of the probe and folding the sleeve over a retaining ring, whichholds the sleeve against the outer surface of the probe Preferably, themethod includes anchoring an everted, outer portion of the sleeve so asto remain substantially stationary relative to a wall of the lumen.

In another preferred embodiment, coupling the sleeve includes holding aportion of the sleeve in a compact state at the proximal end of theprobe, so that the sleeve feeds out from the proximal end as the probeadvances.

Preferably, the lumen includes the gastrointestinal tract of a patient.

The present invention will be more fully understood from the followingdetailed description of the preferred embodiments thereof, takentogether with the drawings, in which.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, sectional illustration of a probe with a foldedsleeve, in accordance with a preferred embodiment of the presentinvention;

FIG. 2 is a schematic, partly sectional illustration, showing the probeof FIG. 1 and associated apparatus in operation, in accordance with apreferred embodiment of the present invention, and

FIG. 3 is a schematic, sectional illustration of a probe with aneverting sleeve, in accordance with another preferred embodiment of thepresent invention

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENTS

FIG. 1 is a schematic, sectional illustration of an endoscopic probe 20,in accordance with a preferred embodiment of the present invention.Probe 20 comprises a probe head or top 22, which is preferablycylindrically shaped with a transparent optical window or lens 30 at itsdistal end The probe contains an electro-optical package 28, whichpreferably includes a light source and miniature video camera, as areknown in the art, which capture images through lens 30. A cable bundle32 includes wires 31, which connect package 28 and an external consolefor use in transmitting information from and to the package.

The probe further comprises a base 24, made up of a cap 34, whichreceives an covers and an internal spindle 36, flanged at its proximalend. A flexible sleeve 26 is folded into the space between the cap andthe spindle, and feeds out of a circular slot formed between the cap andthe spindle at the proximal end of the base Cable 32 preferably passesthrough a hollow bore in the center of spindle 36, as shown in thefigure.

Sleeve 26 preferably comprises a flexible, biocompatible plastic, of anysuitable type known in the art, most preferably with a wall thicknessbetween about 0 1 and 0.5 mm and an overall diameter when inflated ofabout 10 mm. The plastic sleeve 26 is folded and fastened tightly withinbase 24, so as to allow the sleeve to unfold and feed out evenly fromthe proximal to the distal end thereof The distal end of the sleeve isfirmly sealed to probe 20, so the the sleeve can be inflated withpressurized gas or other fluid, as described further hereinbelow.

Preferably, probe 20 includes a steering unit 23, which angles probehead 22 relative to base 24 The steering unit is used to aid in turningthe probe around curves and avoiding obstructions in thegastrointestinal tract. It is also useful in tilting head 22 so as tocapture an image of or perform a surgical procedure on an area ofinterest that is not directly in front of the probe. Most preferably,steering unit 23 comprises a group of opposing bellows 25 and 27, asdescribed in the above-mentioned Israel Patent Application 125,397,which are inflated and deflated by gas or fluid lines 33 within bundle32 in order to turn the unit Although for simplicity, only two suchbellows are shown in the figure, it will be understood that one, three,four or more bellows may actually be used Alternatively, steering unit23 may comprise other types of steering mechanisms, as are known in theendoscopic art, such as mechanisms based on pull-wires

In addition to electro-optic package 28, probe head 22 may also comprisesuction and/or irrigation ports, sensors of various types and/orspecially adapted surgical instruments, such as biopsy forceps. Theseelements are known generally in the art, and are not shown in thefigures. Substantially any suitable type of tool or sensor may beadapted and included in head 22, and coupled to external apparatus byappropriate adaptation of cable 32.

FIG. 2 is a schematic, partly sectional illustration of probe 20 in usefor endoscopic examination of a patient's colon 40, in accordance with apreferred embodiment of the present invention A proximal end of sleeve26 is fixed by a stationary anchor 50, located outside the patient'sbody, to a tube 48, which is coupled to inflation and venting apparatus46. Cable 32 is fed through sleeve 26 and tube 48 via an air-tightcoupling to a console 44.

Probe 20 is inserted into colon 40 through anus 42. Apparatus 46 is thenactuated, for example, by opening a valve therein coupled to aregulated, pressurized source of CO₂ or other gas. Preferably, a gaspressure in the range of 0.3 atm is used to inflate the sleeve.Alternatively, a liquid, such as sterile water, may be used to inflatethe sleeve. Inflating the sleeve propels probe 20 forward into colon 40,thus causing sleeve 26 to unfold and feed out of base 24 of the probe.The inflated portion of the sleeve typically expands radially and maycontact the wall of the colon, but there is generally only minimal or nolongitudinal motion of the sleeve against the wall Thus, rubbing andtrauma to the intestinal wall are minimized.

As probe 20 passes through the colon, steering unit 23 is used asnecessary, as described hereinabove, to turn probe head 22 at an anglerelative to base 24. The steering unit is preferably controlled viaconsole 44 to maneuver the probe around curves and obstructions in thegastrointestinal tract.

When the endoscopic examination is completed, apparatus 46 is operatedto vent sleeve 26. The pressure in the sleeve is relieved, and thesleeve deflates. At this point probe 20 is withdrawn from colon 40,preferably by pulling on cable 32, or on deflated sleeve 26, or both.

FIG. 3 is a schematic, sectional illustration of another probe 60, withan everting sleeve 70, advancing inside colon 40, in accordance with apreferred embodiment of the present invention Probe 60 is generallysimilar in construction and operation to probe 20, describedhereinabove, except for the operation of everting sleeve 70

A base 62 of probe 60 is preferably made of a magnetic metal and/orcontains a permanent magnet Base 62 has two grooves 68, which receiverespective magnetic metal springs 64 and 66, which have the form ofresilient rings The circumference of groove 66 is preferably less thanthe circumference of groove 64, so that spring 64 is longer than spring66 The resilience of springs 64 and 66 and their magnetic attraction tobase 62 serves to retain sleeve 70 between the springs and the base.

Before inserting probe 60 through anus 42, sleeve 70 is passed aroundbase 62, and springs 64 and 66 are fitted around the sleeve and intogrooves 68. Sleeve 70 is then folded outward, or everted, over spring64. An outer portion 78 of the sleeve is drawn through the springs andfastened to an anchor 72. A reserve portion 74 of sleeve 70 is folded orrolled up and held in a position outside the patient's body (as opposedto the case of probe 20, shown in FIG. 1, in which the reserve portionof the sleeve is held in the base of the probe)

To advance probe 60 in colon 40, sleeve 70 is inflated byinflation/venting apparatus 46. Reserve portion 74 unfolds, and an innerportion 76 thereof is pulled behind the probe in a distal direction, asshown by the arrows in FIG. 3, and everts over spring 64. Portion 76,which is moving, is contained inside outer portion 78, which contactsthe wall of colon 40 and is substantially stationary. Thus, frictionwith or trauma to colon 40 are avoided. When it is time to withdrawprobe 60, sleeve 70 is vented, and inner portion 76 is pulled back, awayfrom the patient's body, thus reversing the everting action

Preferably, springs 64 and 66 press sufficiently tightly against sleeve70 in grooves 68, and the sleeve itself is sufficiently elastic, so asto produce a substantially air-tight seal. Thus, the gas that passesthrough reserve portion 74 to inflate the sleeve does not leak out inlarge quantities into colon 40. Alternatively, the space between innerportion 76 and outer portion 78 is inflated to advance probe 60

Although preferred embodiments are described hereinabove with referenceto a device for moving an instrument package through the lowergastrointestinal tract, it will be understood that the novel principlesof the present invention may be used to move objects in other bodycavities, and may also be used to move objects in lumens and otherregions for non-medical applications, as well An example of anon-medical application includes examination within a highly corrosiveor high-temperature environment, where it is not desirable to havemoving parts of a propulsion unit exposed to the environment It is alsounderstood that while the preferred embodiments described hereinabovehave physical data leads and control leads, the propulsion unit andinstrument package can be powered by batteries and can store data and/ortransmit data by wireless communications, as is known in the art.

It will thus be appreciated that the preferred embodiments are citedherein by way of example, and the full scope of the invention is limitedonly by the claims.

1. A method for endoscopic examination, comprising: coupling a proximalend of a flexible sleeve to an anchor unit; coupling a distal end of thesleeve to an internal unit, while gathering at least a portion of thesleeve between the proximal and distal ends in a compact state in theinternal unit; and advancing the internal unit into a gastrointestinaltract of a patient while holding the anchor unit outside thegastrointestinal tract, so that the sleeve feeds out from the internalunit as the internal unit advances such that a proximal part of theportion of the sleeve is extended within the gastrointestinal tractwhile a distal part of the portion of the sleeve remains in the compactstate in the internal unit; inspecting the gastrointestinal tract usingthe internal unit; and deflating the sleeve in order to withdraw theinternal unit from the gastrointestinal tract.
 2. A method according toclaim 1, wherein holding the anchor unit comprises anchoring theproximal end of the sleeve so that the sleeve that has fed out from theinternal unit remains substantially stationary relative to a wall of thegastrointestinal tract as the internal unit is advanced.
 3. The methodof claim 1 wherein advancing the internal unit comprises inflating thesleeve.